Topic
Carroll rearrangement
About: Carroll rearrangement is a(n) research topic. Over the lifetime, 1483 publication(s) have been published within this topic receiving 23513 citation(s).
...read more
Papers
More filters
712 citations
550 citations
435 citations
294 citations
TL;DR: Investigations demonstrate that the counterion of the azolium salt plays a key role in the formation of the catalytically active species in the synthesis of enantioenriched kojic acid derivatives.
...read more
Abstract: In the presence of a chiral azolium salt (10 mol %), enols and ynals undergo a highly enantioselective annulation reaction to form enantiomerically enriched dihydropyranones via an N-heterocyclic carbene catalyzed variant of the Claisen rearrangement. Unlike other azolium-catalyzed reactions, this process requires no added base to generate the putative NHC-catalyst, and our investigations demonstrate that the counterion of the azolium salt plays a key role in the formation of the catalytically active species. Detailed kinetic studies eliminate a potential 1,4-addition as the mechanistic pathway; the observed rate law and activation parameters are consistent with a Claisen rearrangement as the rate-limiting step. This catalytic system was applied to the synthesis of enantioenriched kojic acid derivatives, a reaction of demonstrated synthetic utility for which other methods for catalytic enantioselective Claisen rearrangements have not provided a satisfactory solution.
...read more
261 citations